STAT-Dx Life S.L. (A QIAGEN company), Carrer de Baldiri Reixac, 4-8, 08028 Barcelona, Spain.
STAT-Dx Life S.L. (A QIAGEN company), Carrer de Baldiri Reixac, 4-8, 08028 Barcelona, Spain.
Int J Infect Dis. 2022 Sep;122:930-935. doi: 10.1016/j.ijid.2022.07.022. Epub 2022 Jul 12.
Qualitative real-time polymerase chain reaction tests are not designed to provide quantitative or semiquantitative results because cycle threshold (Ct) values are not normalized to standardized controls of known concentration. The aim of this study was to characterize SARS-CoV-2 viral loads based on Ct values, using the QIAstat-Dx® Respiratory SARS-CoV-2 Panel.
Different lineages of SARS-CoV-2 clinical samples and the World Health Organization international standard were used to assess the linearity of the QIAstat-Dx Respiratory SARS-CoV-2 Panel. Limit of detection for the different lineages was characterized.
Comparable efficiencies and linearity for all samples resulted in R ≥0.99, covering a dynamic range of 1,000,000-100 copies/mL for the SARS-CoV-2 assay, showing linear correlation between Ct values and viral load down to 300 copies/mL.
The SARS-CoV-2 Ct values provided by the QIAstat-Dx® Respiratory SARS-CoV-2 Panel could be used as a surrogate for viral load given the linear correlation between Ct values and viral concentration down to limit of detection. This panel allows to obtain reproducible Ct values for SARS-CoV-2 ribonucleic acid downstream of the sample collection, reducing the sample-to-Ct workflow variability. Ct values can help provide a reliable assessment and comparison of viral loads in patients when tested with the QIAstat-Dx Respiratory SARS-CoV-2 Panel.
由于循环阈值 (Ct) 值未标准化到已知浓度的标准化对照，因此定性实时聚合酶链反应检测不是设计用于提供定量或半定量结果。本研究的目的是使用 QIAstat-Dx®呼吸道 SARS-CoV-2 检测试剂盒，根据 Ct 值来描述 SARS-CoV-2 病毒载量。
使用不同的 SARS-CoV-2 临床样本谱系和世界卫生组织国际标准来评估 QIAstat-Dx 呼吸道 SARS-CoV-2 检测试剂盒的线性度。对不同谱系的检测限进行了表征。
所有样本的效率和线性度相当，R≥0.99，涵盖 SARS-CoV-2 检测 1,000,000-100 拷贝/ml 的动态范围，Ct 值与病毒载量之间呈线性相关，直至 300 拷贝/ml。
由于 Ct 值与病毒浓度之间存在线性关系，直至检测限，QIAstat-Dx®呼吸道 SARS-CoV-2 检测试剂盒提供的 SARS-CoV-2 Ct 值可作为病毒载量的替代物。该试剂盒允许在样本采集后获得 SARS-CoV-2 核糖核酸的可重复 Ct 值，从而降低了样本到 Ct 值的工作流程变异性。Ct 值可帮助在使用 QIAstat-Dx 呼吸道 SARS-CoV-2 检测试剂盒检测时，对患者的病毒载量进行可靠评估和比较。
